WIND AND FLIGHT 151 
losing altitude as he goes. Not unfrequently birds 
change from a left-handed to a right-handed spiral ; 
Gulls are very fond of this; they often describe 
very small “circles,” revolving round the down- 
ward-pointing inner-wing, and it may be that the 
change to the right-handed spiral saves them from 
giddiness. 
Mr. Peal was of opinion that the Adjutants, whose 
soaring he studied so zealously, always made leeway 
as they rose. But there seems to be no reason why 
this should be so. It may have been that what 
looked like ‘a movement to leeward had for its object 
the keeping within an upward slanting stream of air 
on which they depended. There seems no reason 
for an involuntary loss of leeway. Let us consider 
a particular turn of the spiral from start to finish. 
When the bird is facing the wind, he has only to 
incline his body correctly and he will make headway. 
When the wind strikes him from behind, he must 
slope his body downward, otherwise there will be a 
disarrangement of plumage, and there will result a 
slight loss by leeway, though no loss of elevation 
unless the bird so chooses. When he turns his side 
to the wind he is free to set himself at any incline he 
likes, and, according as he chooses, he will advance 
or retreat. During far the greater part of the circle, 
therefore, he is far from being the plaything of the 
wind. Asa matter of fact birds may be seen circling 
over hill-tops without any loss by leeway, and I 
believe I have seen them equally successful over 
plains. There is this, too, to be remembered. When 
a bird has gained all the altitude he wants, by gliding 
slightly downward he can make headway in whatever 
